A147799 Minimal value of A007947(m*(7^n-m)) with m coprime to 7.

6, 6, 30, 30, 282, 2262, 17034, 36006, 71070

Offset

1,1

Comments

The minima are reached for m values given in A147804.

This is related to the abc conjecture.

All terms of this sequence are even, so one could also consider A147799/2 = 3, 3, 15, 15, 141, 1131, 8517, 18003, 35535, ... So far these terms are also multiples of 3, but this might be a coincidence.

Links

Table of n, a(n) for n=1..9.

Prog

(PARI) A147799(n, p=7)={my(m=n=p^n); for(a=1, n\2, a%p || next; m > 2*A007947(a) || next; m > A007947(n-a)*A007947(a) || next; m = A007947(n-a)*A007947(a)); m; }

Crossrefs

Cf. A007947, A147804 (m values); A143702, A147801, A147800 (analog for 2^n, 3^n, 5^n), A147298 (general case).

Sequence in context: A054436 A055522 A078637 * A071021 A279865 A321528

Adjacent sequences: A147796 A147797 A147798 * A147800 A147801 A147802

Keyword

nonn,more

Author

M. F. Hasler, Nov 13 2008

Status

approved